Vaisala HUMICAP MMT310 Manual de servicio descargar pdf (Pagina 44)

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DMT345 and DMT346 Dewpoint Transmitters

for High Temperature Applications

The Vaisala DRYCAP

Dewpoint

Transmitters DMT345 and

DMT346 are designed for humidity

measurement in industrial drying

applications with particularly high

temperatures.

Both transmitters incorporate the

Vaisala DRYCAP

sensor, which is

accurate, reliable, and stable. The

sensor withstands condensation

and is immune to particulate

contamination, oil vapor and most

chemicals. The DRYCAP

sensor

stands out for its swift response time

and rapid recovery after getting wet.

Measure humidity directly

in hot processes

The DMT345 and DMT346 are

constructed for direct measurement

in hot processes. Therefore, there

is no need for sampling systems

and trace heating. As a result,

high accuracy and constancy are

maintained.

The Vaisala DRYCAP

Dewpoint Transmitters DMT345 and DMT346 are designed

to measure and control humidity especially in dry environments with high

temperatures.

The accuracy and stability of the

DMT345 and the DMT346 are due to

the unique auto-calibration function,

patented by Vaisala. This auto-

calibration makes the transmitter

perform a calibration and adjustment

by itself while the measured process

is running. If the measurement

accuracy is not conrmed, corrections

are made automatically. The

procedure is so quick and corrections

are so minor that it will go unnoticed.

This ensures low maintenance

and high performance. In normal

conditions, it is recommended to have

a traceable calibration performed

once a year.

DMT345, Accurate in hot

and dry environments

The DMT345 is designed for accurate

humidity measurement in hot and

dry conditions. This model provides

unmatched dry end measurement

accuracy in temperatures up to 140 °C,

however the DMT345 can operate

safely in temperatures up to 180 °C.

The stainless steel probe is especially

designed for high temperatures and

has an optional installation ange that

allows an adjustable installation depth

and therefore a precise positioning.

Features/Beneﬁts

▪

The DMT345 measures

humidity in temperatures up to

180 °C (356 °F)

▪

The DMT346 measures

humidity in temperatures up to

350 °C (+662 °F)

▪

Dewpoint accuracy ±2 °C

(±3.6 °F)

▪

Vaisala DRYCAP® Sensor

provides accurate, reliable

measurement with excellent

long-term stability and fast

response

▪

Withstands condensation

▪

Unique auto-calibration feature

▪

Optional local display with

keypad, mains power supply

module and alarm relays

▪

NIST traceable calibration

(certiﬁcate included)

▪

Analog outputs, WLAN/LAN

The large and clear display allows the

user to check data at a glance.

Technical data

Measured variables DMT345

DEWPOINT DMT345

Sensor Vaisala DRYCAP

180S

Measurement range -40 ... +100 °C (-40 ... +212 °F) Td

Accuracy ±2°C (±3.6 °F) Td

See the accuracy graph below

Response time 63 % [90 %] ﬂow rate 1 l/min and 1 bar pressure

from dry to wet 5s [10 s]

from wet to dry including auto-calibration 45s [5 min]

Dewpoint accuracy vs. measurement conditions

DMT346, Reliable in very hot processes

When process temperatures range between 140 °C to

350 °C, the DMT346 provides the best measurement

performance.

The DMT346 comes with a cooling set as a standard

feature. The cooling effect may be regulated by adding the

cooling ns, or removing them from the set for the best

measurement performance.

The cooling system operates without moving parts,

additional power or cooling utilities, thereby eliminating

the risk of sensor damage due to a mechanical cooling

failure.

Additionally, sensor warming minimizes the risk of

condensing on the sensor. In low humidity the combination

of auto-calibration and DRYCAP

ensures accurate

measurement.

Graphical display

The DMT345 and DMT346 transmitters can be ordered

with a large numerical and graphical display, which allows

the user to clearly monitor operational data, measurement

trends and up to one-year measurement history.

The optional data logger with real-time clock makes it

possible to generate more than four years of the measured

history and zoom in on any desired time or time frame.

Versatile outputs and (wireless) data

collection

The transmitter can be connected to a network with an

optional (W)LAN interface, which enables a (wireless)

Ethernet connection.

For serial interface also the USB connection, RS232 and

RS485 can be used. Additionally an alarm relay option is

available.

The transmitter can have up to three analog outputs.

Galvanic isolation of supply power and analog outputs

are also offered. The recorded measurement data can be

viewed on the display or transferred to a PC with Microsoft

Windows

software.

Units are delivered installation-ready and meet ROHS

requirements.

TEMPERATURE DMT345

Measurement range 0 ... +180 °C (+32 ... +356°F)

with sensor warming upper range limited by humidity

(at 80% RH warming is switched on and T

reading not actual process Temperature)

Accuracy ±0.4 °C at 100 °C

Temperature sensor Pt 100 IEC 751 1/3 class B

RELATIVE HUMIDITY DMT345

Measurement range 0 ... 100 % RH

with sensor warming 0 ... 80 % RH

Accuracy

below 10 % RH ±10 % of reading

above 10 % RH ±1,5% RH + 1,5 % of reading

MIXING RATIO DMT345

Measurement range (typical) 0 ... 1000 g/kg (0 ... 7000 gr/lbs)

Accuracy (typical) ±12% of reading

1 2 ... 39 40 41 42 43 44 45 46 47 48 49 ... 122 123

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Vaisala HUMICAP MMT310 Manual de servicio Pagina 44

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